SikaRep® Microcrete-4
High performance non-shrink cementitious microconcrete for concrete repair
SikaRep® Microcrete-4 is factory designed pourable, shrinkage compensated, high performance microconcrete with selected cement, aggregate and other chemicals. Recommended water and coarse aggregate to be added at site as per requirement.
- No vibration needed
- Easily pumpable
- Easy to mix and apply
Usage
SikaRep® Microcrete-4 is suitable for producing high performance micro-concrete for deep repairs to all concrete structures such as:
- Highway bridges and culverts
- Whafts and jetties
- Tunnels and mines
- Dams and reservoirs
- Car parks and basements
- Power stations
- Sewerage and water treatment structures
- Anywhere where localised deep repair is required
- Anywhere additional thickness is required (column and beam jacketing, etc.)
- Structrural strengthening of structure by section enlargement
Packaging
30 kg bag
Advantages
- No vibration needed
- Easily pumpable
- Easy to mix and apply
- Excellent flow characteristics
- Rapid strength development
- High ultimate strengths
- Impact resistant
- Non-corrosive
- Non-toxic
- Iron and chloride free
- Dense and non-shrink concrete created by dual stage expansion
- Good bonding with existing concrete
- Adjustable consistency by controlling the water within the recommended limit
Colour
Powder / Grey
Product Details
APPROVALS / STANDARDS
- Test Certificate No. C1/0000227197, Shriram Institute for Industrial Research, dated 07-09-2020
- Test Report, IIT Bombay, dated March 10, 2015
- Consultancy Report, IIT Delhi, 2014
Chemical Base
Portland cement, selected fillers and aggregates, special additives
Shelf Life
6 months from date of production
Storage Conditions
Store in dry conditions at temperatures between +10°C and +40°C. Protect from direct sunlight and frost.
Compressive strength
Curing time | Compressive strength |
| 1 day | ≥ 25 N/mm2 |
| 3 days | ≥ 35 N/mm2 |
| 7 days | ≥ 45 N/mm2 |
| 28 days | ≥ 65 N/mm2 |
Values measured at water : powder = 0.15, cube size 70.6 mm, curing temperature +30 °C
Flexural strength
Curing time | Flexural strength |
| 7 days | ≥ 8 N/mm2 |
| 28 days | ≥ 9 N/mm2 |
Values measured at water : powder = 0.15, curing temperature +30 °C
Splitting tensile strength
≥ 3.5 N/mm2 (water : powder = 0.15, 28 days, +30 °C) | (ASTM C496) |
Shrinkage
No shrinkage after initial setting
Expansion
Up to 4 % | (ASTM C1090) |
Application
Mixing ratio
Water : Powder = 0.14 to 0.16 (by weight)
4.2 L to 4.8 L water per 30 kg bag, dependent on the desired flow
Fresh mortar density
| (2.15 ± 0.15) kg/L (water : powder = 0.15) | (EN ISO 2811-1) |
Layer thickness
Minimum | 25 mm per pour |
Maximum | 100 mm per pour |
Higher layer thickness can be done with addition of aggregates. Contact Sika Technical Services for additional information.
Ambient air temperature
+5 °C min. / +40 °C max.
Substrate temperature
+5 °C min. / +40 °C max.
Pot life
~20 minutes (water : powder = 0.15, +30 °C)
Consumption
~1900 kg of powder per m3 of concrete (water : powder = 0.15)
EQUIPMENT
SikaRep® Microcrete-4 can be mixed both in paddle type and slow speed (max. 500 rpm) grouting mixer or drum type concrete mixer.
MIXING
- Place about 80–90 % of the premeasured clean water into a clean mixer and gradually add the whole bag of SikaRep® Microcrete-4 into it while continuously mixing.
- Add the remaining water and additional clean 5–10 mm aggregates (if needed as per design) until the desired consistency is obtained.
- Mixing time should be minimum 3 minutes.
IMPORTANT
Concrete can also be produced with addition of 10 mm down properly graded silt-free aggregate in proportion of 2 : 1 (SikaRep® Microcrete-4 : coarse aggregate) by weight.
IMPORTANT
Do not mix more material, which cannot be used within pot life.
IMPORTANT
Do not add extra water.
IMPORTANT
Mix only full bags for best results.
APPLICATION
Strictly follow installation procedures as defined in method statements, application manuals and working instructions which must always be adjusted to the actual site conditions.
IMPORTANT
Formwork
Ensure formwork is secure and watertight to prevent movement and leaking during placing and curing.
IMPORTANT
Working in thick sections
Do not pour more than 100 mm of layer thickness without addition of aggregates.
Small localised repairs
Small volume mixing may carried out with a suitable low-speed (500 rpm) drill and mixing paddle. After mixing, stir lightly with a spatula for a few seconds to release any entrapped air. The microconcrete is then poured immediately into the prepared formwork.
Large repairs
When carrying out large scale repairs or column / beam jacketing, ensure sufficient pressure head is maintained for uninterrupted concrete flow. Formwork must be firmly placed and kept watertight. When placing microconcrete over large area, it is important to maintain a continuous flow throughout the process. Work sequence and equipment must be properly organised to ensure an uninterrupted flow of microconcrete. Ensure proper air displacement when pouring. In large areas, microconcrete may be mixed and pumped using heavy duty screw feed and piston pumps. Equipment suitability should be tested and checked prior to actual grouting works.
Cold weather working
Consider storing bags in a warm environment and using warm water to assist with achieving strength gain and maintaining physical properties.
Hot weather working
Consider storing bags in a cool environment and using cold water to assist with controlling the exothermic reaction to reduce cracking and maintaining physical properties.
CURING TREATMENT
Formwork must remain in place for at least 3 days. Upon removal of the formwork, cure the exposed surfaces immediately with Sika Antisol® curing compound or use other approved curing methods.
CLEANING OF TOOLS
Clean all tools and application equipment with water immediately after use. Hardened or cured material can only be removed mechanically.